My Dog Ate a Highlighter – What Should I Do?

Dogs are generally known to be such curious creatures; for that reason, they might want to try to chew certain objects or even swallow them. These objects can include some toys, furballs, or even something as weird as a highlighter! This is related to their natural instinctive urge to chew bones or can even occur due to boredom. Additionally, this behavior is just one of their sensory ways to explore their environment as well as the objects around them.

Generally, this behavior is not very pleasant to dog owners as they will always be concerned about their pet’s health. Sometimes, this behavior will not cause any serious trouble, but at other times it can lead to significant physiological problems. These can include poisoning, intestinal obstruction, or even intestinal bleeding. 

If your dog ate a highlighter, you might want to contact your veterinarian immediately. But if you are not in immediate reach of a vet at the moment, we are here to answer all of the questions roaming your mind. We will explain all of the symptoms that show the presence of a significant physiological problem, and we will help you understand how serious your dog’s state is. 

What Happens if My Dog Eats a Highlighter?

To understand the consequences of swallowing a highlighter, we might want to break down the components of this object. Generally, highlighters are made up of plastic material which contains a small sponge holding the highlighter’s ink. Mostly, the plastic and ink components of the highlighter are the ones that impose a risk on your dog’s health.

The plastic by itself is a very harmful object for your dog’s gastrointestinal tract as it can cause an obstruction in the intestines or even damage the intestinal wall, causing severe bleeding. If there are any sharp parts in the plastic material, it can easily cause scratches and wounds all along the alimentary tract. Injuries can occur in the oral cavity, the pharynx, and even in the intestinal wall causing unfavorable bleeding. 

You can detect this kind of damage by following up with the symptoms your dog is showing: These include diarrhea, repetitive vomiting, loss of appetite, and abdominal bloating. You can also be able to detect noticeable abdominal pain, restlessness, and discomfort in your dog. To ensure your pet’s gastrointestinal health after the accident, you can help your dog’s digestion by using several supplements.

Are Highlighter Pens Poisonous to Dogs?

Highlighter ink usually contains pigments, dyes, resin, and other chemical substances, usually harmless in certain amounts. Therefore complications may occur depending on the type of ink and the amount ingested. The ink portion of the highlighter is the one capable of causing probably poisoning.

Ink is non-toxic for dogs unless ingested in large quantities, and this won’t be a huge issue regarding the amount of ink found in highlighters. The symptoms that might be visible after ingestion of highlighter ink are a stained oral mucosa, colored tongue, and slightly disturbed digestion. Fortunately, the highlighter’s ink is not as dangerous as the plastic components.

On the other hand, if a large quantity of ink is ingested, the poisoning signs may include vomiting, diarrhea in addition to lethargy, disorientation, and in severe cases, it can cause seizures. But in general, the small amount of ink present in one highlighter will not cause a serious pathological condition. Therefore, if your dog ate a highlighter pen, don’t be concerned with the pen’s poisoning effects because it will probably cause no harm to your dog’s health.

What Should I Do if My Dog Ate a Highlighter?

If you were ever placed in a situation where your dog starts chewing and swallowing a highlighter pen, you should instantly contact your veterinarian. Get your dog to the nearest vet hospital and allow the vets to handle the situation. If you are not in immediate reach with a specialized doctor, try to perform a primary approach to minimalize the general damages. 

If you want to perform an emergency course of action yourself, the first thing you should do is check for any plastic parts that can be stuck in your dog’s throat. If there are any plastic obstructions in your dog’s airways, your pet may choke and lose its ability to breathe. Therefore, try to carefully remove any visible foreign object in your dog’s mouth or pharynx, and make sure that you’re not causing any scratches or wounds. 

After you finally deliver your dog to the vet, follow all the appropriate treatments and procedures recommended by the doctor. Afterward, you can try to improve your dog’s general medical condition and use some probiotics for dogs to develop your dog’s gut health. Make sure that your dog stays away from any other small, harmful objects that can cause serious issues to your pet’s health. 


After all, dogs are always eager to explore everything around them, making them exhibit certain behaviors and weird habits. Additionally, these behaviors are mostly related to their instinctive urge to bite objects like bones and chew on them. All we can do is try to remove any toxic or harmful objects away from them and provide them with certain toys that will keep the boredom away. Dogs consuming highlighters is an alarming situation that needs instantaneous medical attention, in addition to certain supplements to restore your dog’s immunity and gut health.


  • Brad

    Hi I'm Brad, the founder of Having been a vet of 6 years I work alongside our team to provide valuable insight into your dog's health. I have a frenchie myself named Senzu who is my pride and joy!

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